baby syndrome is a term used to describe the
constellation of signs and symptoms resulting
from violent shaking or shaking and impacting of
of an infant or small child. The degree of brain
damage depends on the amount and duration of the
shaking and the forces involved in impact of the head.
Signs and symptoms range on a spectrum of neurological
alterations from minor (irritability, lethargy,
tremors, vomiting) to major (seizures, coma, stupor,
death). These neurological changes are due to
destruction of brain cells secondary to trauma, lack
of oxygen to the brain cells, and swelling of the
brain. Extensive retinal hemorrhages in one or both
eyes are found in the vast majority of these cases.
The classic triad of subdural hematoma, brain swelling
and retinal hemorrhages are accompanied in some, but
not all, cases by bruising of the part of the body
used as a "handle" for shaking. Fractures of
the long bones and/or of the ribs may also be seen in
some cases. In many cases, however, there is no
external evidence of trauma either to the head or the
body. (Definition provided by
Approximately 20% of
cases are fatal in the first few days after injury and
the majority of the survivors are left with
handicaps ranging from mild - learning disorders,
behavioral changes - to moderate and severe, such as
profound mental and developmental retardation,
paralysis, blindness, inability to eat or exist in a
permanent vegetative state.
In a response provided
by Dr. John Lancon, he defined shaken baby syndrome as
the constellation of non-accidental intracranial and
ocular hemorrhages occurring in infants and young
children. Other injuries, including cutaneous bruises,
lacerations, burns, parenchymal brain injuries, rib
fractures, extremity fractures, and injuries to
various internal organs may be seen in the setting of
shaken baby syndrome, but are not required for
diagnosis. Some experts have suggested changing the
name of the syndrome to shaken impact syndrome to
emphasize the importance of cranial impact in the
genesis of the severe brain injury seen in some
victims of shaken baby syndrome.
|There are no firm statistics regarding the actual incidence of SBS/SIS since there are no central reporting registries to collect these data. However, estimates have been made based on clinical experience and extrapolated figures from hospitals caring for children. Estimates range from annual figures as low as 600 cases per year in the United States to as high as 1400. Until a method for collecting such statistics is established, the true incidence will not be known. It is recognized, however, that it is the most common cause of mortality and accounts for the most long-term disability in infants and young children due to physical child abuse. The age of the victims range from the newborn period to 4 years of age. The vast majority of SBS/SIS occur before the infant's first birthday and the average age of the victim is between 3 and 8 months of age.|
|THE SCENARIO FOR SHAKEN BABY / SHAKEN IMPACT SYNDROME|
|The usual trigger for shaking a
baby is inconsolable crying in the infant.
Frustrated by attempts to console the baby, the
perpetrator loses control and grabs the infant,
either by the chest, under the arms, or by the
arms and violently shakes the baby. The time of
shaking varies, usually ranging from around 5
seconds to 15 or 20 seconds. It has been
estimated by video recordings of a person
shaking a doll of approximate size and weight
that the number of shakes ranges between 2 to 4
per second. During shaking, the head rotates
wildly on the axis of the neck creating multiple
forces within the head. The infant stops crying
and stops breathing, causing decreased oxygen
supply to the body, particularly to the brain.
The infant brain, having a much higher water
content that the adult brain, is much softer
that an adult brain. The absence of myelination,
the "insulation" of the nerve cells
acquired during development of the nervous
system, contributes to the relative softness.
These factors make the brain more gelatinous and
during shaking is more easily distorted and
compressed within the skull. Shaking and the
sudden deceleration of the head at the time of
impact does several things:
The combined effect is massive traumatic destruction of the brain tissue, leading to immediate brain swelling and causing enormous increases in the pressure within the skull. This swelling compounds the problem, since swelling causes compression of the blood vessels and decreases the oxygen supply to the brain.
It is these injuries to the brain, not the bleeding under the Dura or the Arachnoid Membranes that cause the signs, symptoms, and course of Shaken Baby/Shaken Impact Syndrome.
Concomitant with the destruction of the brain tissue are other injuries. The most significant of these are the retinal hemorrhages. There are a number of theories to explain retinal hemorrhages in SBS/SIS. One states that they are the result of transmitted pressure within the skull. The argument against this is that retinal hemorrhages occur with much less frequency in infants whose brain injuries are due to accidental causes with similar increased pressures within the skull, such as those resulting from motor vehicle accidents. Another theory is that retinal hemorrhages occur because shaking causes disruption of the layers of the retina. There are 10 layers on the retina, all richly supplied with blood vessels. Proponents of this theory state that when these layers are subjected to the lines of force associated with shaking, they slide across one another, stretching these vessels so that they also shear and bleed.
The retinal hemorrhages seen in SBS/SIS are variable ranging from a few scattered hemorrhages to extensive hemorrhages involving multiple layers of the retina. Retinal hemorrhages seen in other conditions are usually closer to the surface, so-called preretinal hemorrhages, and resolve quickly. Retinal hemorrhages are not seen as the result of cardiopulmonary resuscitation or accidental short falls.
A number of other lesions are variable findings in SBS/SIS. These include skull fractures resulting from the impact when the infant is thrown against a hard or soft surface; fractures of the posterior arcs of the ribs near the spine due to the levering of the fingers of the hands of the perpetrator while holding the baby during shaking; fractures of the clavicles (collarbone); and fractures of the long bones. Long bone fractures are attributed to the flailing of the arms and legs during shaking. Bruising of the skin of the head, face and body may also occur. It is uncommon to see injuries to the bones, interspinous ligaments and muscles of the neck, probably due to the underdevelopment of these structures in the infant. It is also uncommon to see injuries to the spinal cord in cases of SBS/SIS.
|SYMPTOMS AND PHYSICAL FINDINGS|
|Symptoms and physical findings
are variable, depending on the length and
severity of the shaking and whether the infant
was thrown onto a surface. The syndrome can be
seen as a continuum from a short duration of
shaking with little or no impact, to severe,
prolonged shaking and major impact. The
resulting signs and symptoms may run the gamut
from decreased responsiveness, irritability,
lethargy and limpness, - through convulsions,
vomiting from increased pressure within the
skull, increased breathing rate, low body
temperature and low heart rate, - to coma with
fixed and dilated pupils - to death. All of
these symptoms are caused by generalized brain
swelling secondary to trauma with these symptoms
beginning immediately after the shaking and
reaching their peak within 4-6 hours.
It is important to state that there is no evidence to support the concept that re-bleeding of an older subdural hematoma can result from trivial injury and cause an infant to suddenly collapse and die. The subdural bleeding is only significant in that it is a marker for the traumatic episode to the brain that produces all the clinical signs and symptoms. Even of such a re-bleeding should occur, it does not cause traumatic injury to the brain.
There is no evidence that the findings in SBS/SIS can result from accidental falls in the home, including falls down stairs, off beds or tables, or from caretaker's arms. SBS/SIS results from a violent inflicted injury producing immediate signs and symptoms.
Robert M. Reece, M.D.
Materials are derived from the
Costs Associated with SBS
Facts about SBS
who continue receiving medical treatment and
in-home nursing are typically at a cost of about
$180,000 a year.
experts believe the costs could be as much as
$15 million over a lifetime.
Children who continue receiving medical treatment and in-home nursing are typically at a cost of about $180,000 a year.
Some experts believe the costs could be as much as $15 million over a lifetime.
Offenders and Vicitms of SBS
The above statistics are from the
National Shaken Baby Coalition